Stamp mill



Sept 17, 1935. R, E. MCCALEB 'zmwm STAMP MILL Filed April 17, 1934 2 Sheets-Sheet 1 Sept. 17, 1935.

R. E. M CALEB STAMP MILL Filed April 17, 1954 2 Sheets-Sheet 2 Patented Sept. 17, 1935 UNITED STAT-S ATENT orrls Claims.

This invention relates to a stamp mill, and it is primarily an object of the invention to provide an apparatus of this kind of a balanced type and which is constructed and assembled in a manner to assure a maximum of efiiciency with a minimum of power.

Another object of the invention is to provide a mill of this kind comprising a plurality of stamps together with a mounting and operation for such stamps whereby no two stamps hit at the same time.

The invention consists in, the details of construction and in the combination and arrangement of the several parts of my improved stamp mill whereby certain important advantages are attained and the device rendered simpler, less expensive and otherwise more convenient and advantageous for use, as will be hereinafter more fully set forth.

The novel features of my invention will hereinafter be definitely claimed.

In order that my invention may be the better understood, I will now proceed to describe the same with reference to the accompanying drawings, whereinr- Figure l is a view in elevation of a stamp mill constructed in accordance with an embodiment of my invention with portions of the mortars broken away;

Figure 2 is a fragmentary detailed sectional view taken substantially on the line 22 of Figure 1;

Figure 3 is an enlarged fragmentary detailed sectional view taken substantially on the line 3-3 of Figure 1;

Figure 4 is an enlarged fragmentary detailed sectional view taken substantially on the line 4-4 of Figure 1;

Figure 5 is a view in plan of the operating shaft for the mill assembly as herein embodied;

Figure 6 is a view in end elevation of the shaft as illustrated in Figure 5.

Figure 1 of the accompanying drawings illustrates a unit comprised in my improved stamp mill, it being understood that as many of said units may be employed as preferred. As indicated by the cranks I comprised in the operating or power shaft 2, as illustrated in Figures 5, 6, said units are of an uneven number so that no spaced mortars M in which of each coacts a stamp 3 for effectively crushing the material placed within the mortar. Each of the stamps 3 is carried by the lower end portion of a stamp stem 4 vertically disposed and having reciprocal endwise movement between the guide rollers 5. These rollers 5 as herein disclosed are rotatably supported by and within a bracket 6 secured to the adjacent side member 1 of the mill frame F.

As illustrated in Figure 1, the stamps 3 are in 10 neutral position and the upper end portions of the stems 4 are hingedly connected, as at 8, with the extremities of the balanced spring 9 herein disclosed as of a leaf type. The central portion of 7, this spring 9 is operatively secured, as at it, with a rock arm II depending fro-m the top or crown member I2 of the frame F. As the arm II is rocked or oscillated the stems 4 alternately raise and lower to elfect the desired crushing action of the stamps 3 upon the material within the mortars M, the spring 9 of course effectively compensating for various inequalities appearing during the crushing operation.

As herein disclosed, the arm II depends and has its free end portion operatively connected, as at M, to a rod I5 which is also operatively connected, as at it, with one of the crank arms I of the shaft 2 so that as the shaft 2 is rotated the desired raising and lowering of the stems 4 is effected. The shaft 2 may be rotated in any desired manner as by a belt leading from a suitable source of power and engaged with a pulley I I carried by the shaft 2.

As herein disclosed the arm II is fixed to an end portion of a stub shaft I8 rotatably disposed 85 through and held by a pair of bearing plates I9 depending from the top or crown member I2 of the frame F and spaced transversely thereof. Secured, as at 2!), to this member I2 between the plates I9 is the central portion of a rebound leaf spring 2| each extremity of which having associated therewith an expansible coil spring 23 interposed between said extremity of the spring 2I and a head 24 positioned above the spring 2i.

As herein disclosed the rock arm II is outwardly spaced from the stub shaft I8 and carries the laterally directed member I8 with which is directly made the securing I0 of the spring 9 so that the spring 9 will rock or oscillate with the arm II. This mounting of the spring 9 materially facilitates the desired functioning of the stamps 3 carried by the lower end portions of the stems 4.

This head 24 is carried by the lower end portion of a shank 25 threaded through the member l2 whereby effective means are provided for regulating or varying the tension of the spring 23 in accordance with the requirements of practice.

From the foregoing description it is thought to be obvious that a stamp mill constructed in accordance with my invention is particularly well adapted for use by reason of the convenience and facility with which it may be assembled and operated, and it will also be obvious that my invention is susceptible of some change and modification without departing from the principles and spirit thereof and for this reason I do not wish to be understood as limiting myself to the precise arrangement and formation of the several parts herein shown in carrying out my invention in practice except as hereinafter claimed.

I claim:

1. A stamp mill unit comprising a pair of vertically disposed stamp stems, a horizontally disposed leaf spring having its extremities operatively engaged with the upper portions of the stems, a rock arm swinging on a horizontally disposed axis, means for securing the central portion of the spring to the rock arm for rocking movement therewith, and means for imparting rocking movement to the arm.

2. A stamp mill unit comprising a pair of vertically disposed stamp stems, a horizontally disposed leaf spring having its extremities hingedly connected with the upper portions of the stems, a rock arm swinging on a horizontally disposed axis, means for securing the central portion of the spring to the rock arm for rocking movement therewith, means for imparting rocking movemovement therewith, means for imparting rocking movement to the arm, and a leaf rebound spring positioned above the first named spring.

4. A stamp mill unit comprising a pair of vertically disposed stamp stems, a horizontally disposed leaf spring having its extremities operatively engaged with the upper portions of the stems, a rock arm swinging on a horizontally disposed axis, means for securing the central portion of the spring to the rock arm for rocking movement therewith, means for imparting rocking movement to the arm, a leaf rebound spring positioned above the first named spring, and means for varying the tension of the rebound spring.

5. A stamp mill unit comprising a pair of ver- 25 

